Virus infections after transplantation in man. Brief review

Adenoviral cytopathic changes in pleural fluid: A unique cytological presentation mimicking malignancy

Adenoviruses are emerging as important viral pathogens in immunocompromised patients due to immunodeficiency diseases and recently hematopoietic stem cell and solid organ transplant recipients, impacting morbidity and even mortality. Immunocompromised children are prone to respiratory infection, due to alterations in their immune system. When confronted with diseases involving the pleural effusions, such as viral infections, the diagnostic problem becomes more complex and special effort is needed to recognize and characterize them accurately and to differentiate them from other pathologies such as malignancies. However, cytology of adenoviral infection in pleural effusions has not been reported before. We report a case of an adenovirus infection of the pleural effusion which included lymphocytosis associated with background atypical cells showing a cytopathic effect (cytoplasmic viral particles). The differential diagnosis included lymphoma and infections. Immunohistochemical stain for adenovirus was positive and confirmed by molecular studies. Usually in viral infections there are cytopathic changes due to viral particles affecting epithelial cells but this case is unique as the viral particles were identified in macrophages. We discuss the significance of such infection in comparison with other viral changes indigenous to the pleural effusions, which could also occur in such specimens.

Human Cytomegalovirus Mediates Unique Monocyte-to-Macrophage Differentiation through the PI3K/SHIP1/Akt Signaling Network

Blood monocytes mediate the hematogenous dissemination of human cytomegalovirus (HCMV) in the host. However, monocytes have a short 48-hour (h) lifespan and are not permissive for viral replication. We previously established that HCMV infection drives differentiation of monocytes into long-lived macrophages to mediate viral dissemination, though the mechanism was unclear. Here, we found that HCMV infection promoted monocyte polarization into distinct macrophages by inducing select M1 and M2 differentiation markers and that Akt played a central role in driving differentiation. Akt's upstream positive regulators, PI3K and SHIP1, facilitated the expression of the M1/M2 differentiation markers with p110δ being the predominant PI3K isoform inducing differentiation. Downstream of Akt, M1/M2 differentiation was mediated by caspase 3, whose activity was tightly regulated by Akt in a temporal manner. Overall, this study highlights that HCMV employs the PI3K/SHIP1/Akt pathway to regulate caspase 3 activity and drive monocyte differentiation into unique macrophages, which is critical for viral dissemination.

Prognostic Value of the Burden of Cytomegalovirus Colonic Reactivation Evaluated by Immunohistochemical Staining in Patients with Active Ulcerative Colitis

BACKGROUND

Colonic cytomegalovirus [CMV] reactivation has been involved in steroid refractoriness in patients with active ulcerative colitis [UC]. The benefits of antiviral therapy in this clinical setting are still under debate, but the burden of viral reactivation has been associated with a poorer outcome in some studies. Our aim was to assess whether the burden of CMV reactivation measured by the number of viral inclusions by immunohistochemistry [IHC-CMV] is associated with a risk of colectomy.

METHODS

Biopsy sets of UC patients with positive IHC-CMV were identified from the Pathology departments of three university hospitals. All biopsies were reviewed by expert pathologists, and the maximum number of IHC-CMV-positive cells in each biopsy set was re-assessed. Epidemiological and clinical features and clinical outcomes were recorded.

RESULTS

Forty-six positive IHC-CMV cases with UC were included. At the time of CMV reactivation, 70% were receiving corticosteroids, 33% azathioprine, and 24% anti-tumour necrosis factor [TNF] agents. Thirty-two patients [70%] were treated with antiviral therapy. The median number of IHC-CMV-positive cells was 2 cells/biopsy [IQR 1-4]. Fourteen patients [30%] underwent colectomy, and 4 of them [29%] showed persistence of CMV in the surgical specimen. In the multivariate analysis, colectomy was only associated with >2 positive cells/biopsy [p = 0.048] and younger age [p = 0.023].

CONCLUSIONS

The burden of CMV colonic reactivation in patients with active UC, as measured by IHC, seems to be related to the risk of colectomy, and more data is needed to understand whether antiviral therapy guided by CMV burden will alter the clinical outcome.

Aberrant regulation of the Akt signaling network by human cytomegalovirus allows for targeting of infected monocytes

Primary peripheral blood monocytes are responsible for the hematogenous dissemination of human cytomegalovirus (HCMV) following a primary infection. In order to facilitate viral spread, HCMV extends the naturally short 48-h lifespan of monocytes by stimulating a non-canonical activation of Akt during viral entry, which leads to the increased expression of a specific subset of antiapoptotic proteins. In this study, global analysis of the Akt signaling network showed HCMV induced a more robust activation of the entire network when compared to normal myeloid growth factors. Furthermore, we found a unique interplay between HCMV-activated Akt and the stress response transcription heat shock factor 1 (HSF1) that allowed for the synthesis of both cap- and internal ribosome entry site (IRES)-containing antiapoptotic mRNAs such as myeloid cell leukemia-1 (Mcl-1) and X-linked inhibitor of apoptosis (XIAP), respectively. As generally a switch from cap-dependent to IRES-mediated translation occurs during cellular stress, the ability of HCMV to concurrently drive both types of translation produces a distinct milieu of prosurvival proteins needed for the viability of infected monocytes. Indeed, we found inhibition of XIAP led to death of ∼99% of HCMV-infected monocytes while having minimal effect on the viability of uninfected cells. Taken together, these data indicate that the aberrant activation of the Akt network by HCMV induces the upregulation of a unique subset of antiapoptotic proteins specifically required for the survival of infected monocytes. Consequently, our study highlights the possibility of exploiting these virus-induced changes to prevent viral spread in immunocompromised patients at high-risk for HCMV exposure.

Human Cytomegalovirus Induces an Atypical Activation of Akt To Stimulate the Survival of Short-Lived Monocytes

Human cytomegalovirus (HCMV) is a pervasive herpesvirus responsible for significant morbidity and mortality among immunodeficient/naive hosts. Following a primary HCMV infection, circulating blood monocytes mediate the systemic spread of the virus. Extending the short 48-h life span of monocytes is critical to the viral dissemination process, as these blood-borne cells are nonpermissive for virus replication until they are fully differentiated into macrophages. Here, we show that HCMV glycoprotein gB binding to cellular epidermal growth factor receptor (EGFR) during HCMV entry initiated a rapid (within 15 min) activation of the apoptosis suppressor Akt, which was maintained through 72 h. The virus-induced activation of Akt was more robust than that with the normal myeloid growth factor macrophage colony-stimulating factor (M-CSF) and was essential for infected monocytes to bypass the 48-h viability checkpoint. Activation of phosphoinositide 3-kinase (PI3K) following EGFR engagement by HCMV mediated the phosphorylation of Akt. Moreover, HCMV entry drove a switch away from the PI3K p110δ isoform, which was required for the viability of uninfected monocytes, to the p110β isoform in order to facilitate the Akt-dependent prosurvival state within infected cells. Simultaneously, in contrast to M-CSF, HCMV promoted a rapid increase in SH2 domain-containing inositol 5-phosphatase 1 (SHIP1) expression, leading to signaling through a noncanonical Akt activation pathway. To ensure maximum Akt activity, HCMV also induced an early phosphorylation-dependent inactivation of the negative regulator phosphatase and tensin homolog. Overall, our data indicate that HCMV hijacks the upstream Akt signaling network to induce a nontraditional activation of Akt and subsequently a prosurvival decision at the 48-h cell fate checkpoint, a vital step for HCMV's dissemination and persistence strategy.

IMPORTANCE

HCMV is found throughout the world with a prevalence of 55 to 100% within the human population. HCMV infection is generally asymptomatic in immunocompetent or naive individuals but is a significant cause of morbidity and mortality among the immunocompromised. Widespread organ inflammation is associated with symptomatic infections, which is a direct consequence of the viral dissemination strategy. Inflammatory peripheral blood monocytes facilitate the spread of HCMV. However, HCMV must subvert the naturally short life span of monocytes. In this work, we demonstrate that HCMV induces the activation of Akt, an antiapoptotic protein, in a manner distinct from that of normal myeloid growth factors. Moreover, we decipher how HCMV dysregulates the upstream Akt signaling network during viral entry to promote an Akt-dependent prosurvival state following infection. Delineation of the virus-specific mechanisms that regulate cellular prosurvival pathways in order to drive the survival of HCMV-infected monocytes is important to identifying new anti-HCMV therapeutic targets.

Inhibition of Ganciclovir-Resistant Human Cytomegalovirus Replication by Kampo (Japanese Herbal Medicine)

We examined the effect of Kampo on the replication of ganciclovir (GCV)-resistant human cytomegalovirus (HCMV) in the human embryonic fibroblast cell line MRC-5. Treatment of HCMV-infected cells with Sho-seiryu-to (SST; Xiao-Qing-Long-Tang in Chinese) resulted in the inhibition of viral replication without affecting the cell growth. SST treatment decreased the synthesis of viral DNA, but had no virucidal effect on cell-free HCMV. However, the inhibitory effect of SST on HCMV replication was ablated by anti-interferon-β (IFN-β) antibody suggesting that SST inhibits the replication of GCV-resistant HCMV through the induction of IFN-β. These results suggest that SST is a novel compund with potential as an anti-HCMV.

Human Cytomegalovirus Stimulates the Synthesis of Select Akt-Dependent Antiapoptotic Proteins during Viral Entry To Promote Survival of Infected Monocytes

Primary peripheral blood monocytes are responsible for the hematogenous dissemination of human cytomegalovirus (HCMV) following a primary infection. To facilitate viral spread, we have previously shown HCMV to extend the short 48-h life span of monocytes. Mechanistically, HCMV upregulated two specific cellular antiapoptotic proteins, myeloid leukemia sequence 1 (Mcl-1) and heat shock protein 27 (HSP27), to block the two proteolytic cleavages necessary for the formation of fully active caspase 3 and the subsequent initiation of apoptosis. We now show that HCMV more robustly upregulated Mcl-1 than normal myeloid growth factors and that Mcl-1 was the only myeloid survival factor to rapidly induce HSP27 prior to the 48-h cell fate checkpoint. We determined that HCMV glycoproteins gB and gH signal through the cellular epidermal growth factor receptor (EGFR) and αvβ3 integrin, respectively, during viral entry in order to drive the increase of Mcl-1 and HSP27 in an Akt-dependent manner. Although Akt is known to regulate protein stability and transcription, we found that gB- and gH-initiated signaling preferentially and cooperatively stimulated the synthesis of Mcl-1 and HSP27 through mTOR-mediated translation. Overall, these data suggest that the unique signaling network generated during the viral entry process stimulates the upregulation of select antiapoptotic proteins allowing for the differentiation of short-lived monocytes into long-lived macrophages, a key step in the viral dissemination strategy.

IMPORTANCE

Human cytomegalovirus (HCMV) infection is endemic within the human population. Although primary infection is generally asymptomatic in immunocompetent individuals, HCMV is a significant cause of morbidity and mortality in the immunocompromised. The multiorgan inflammatory diseases associated with symptomatic HCMV infection are a direct consequence of the monocyte-mediated systemic spread of the virus. In order for peripheral blood monocytes to facilitate viral dissemination, HCMV subverts the short 48-h life span of monocytes by inducing the expression of cellular antiapoptotic proteins Mcl-1 and HSP27. Here, we demonstrate that the rapid and simultaneous upregulation of Mcl-1 and HSP27 is a distinctive feature of HCMV-induced monocyte survival. Moreover, we decipher the signaling pathways activated during viral entry needed for the robust synthesis of Mcl-1 and HSP27. Identifying the virus-specific mechanisms used to upregulate select cellular factors required for the survival of HCMV-infected monocytes is important to the development of new classes of anti-HCMV drugs.

Human Cytomegalovirus Promotes Survival of Infected Monocytes via a Distinct Temporal Regulation of Cellular Bcl-2 Family Proteins

Monocytes play a key role in the hematogenous dissemination of human cytomegalovirus (HCMV) to target organ systems. To infect monocytes and reprogram them to deliver infectious virus, HCMV must overcome biological obstacles, including the short life span of monocytes and their antiviral proapoptotic response to infection. We have shown that virally induced upregulation of cellular Mcl-1 promotes early survival of HCMV-infected monocytes, allowing cells to overcome an early apoptotic checkpoint at around 48 h postinfection (hpi). Here, we demonstrate an HCMV-dependent shift from Mcl-1 as the primary antiapoptotic player to the related protein, Bcl-2, later during infection. Bcl-2 was upregulated in HCMV-infected monocytes beginning at 48 hpi. Treatment with the Bcl-2 antagonist ABT-199 only reduced the prosurvival effects of HCMV in target monocytes beginning at 48 hpi, suggesting that Mcl-1 controls survival prior to 48 hpi, while Bcl-2 promotes survival after 48 hpi. Although Bcl-2 was upregulated following viral binding/signaling through cellular integrins (compared to Mcl-1, which is upregulated through binding/activation of epidermal growth factor receptor [EGFR]), it functioned similarly to Mcl-1, adopting the early role of Mcl-1 in preventing caspase-3 cleavage/activation. This distinct, HCMV-induced shift from Mcl-1 to Bcl-2 occurs in response to a cellular upregulation of proapoptotic Bax, as small interfering RNA (siRNA)-mediated knockdown of Bax reduced the upregulation of Bcl-2 in infected monocytes and rescued the cells from the apoptotic effects of Bcl-2 inhibition. Our data demonstrate a distinct survival strategy whereby HCMV induces a biphasic regulation of cellular Bcl-2 proteins to promote host cell survival, leading to viral dissemination and the establishment of persistent HCMV infection.

IMPORTANCE

Hematogenous dissemination of HCMV via infected monocytes is a crucial component of the viral survival strategy and is required for the establishment of persistent infection and for viral spread to additional hosts. Our system of infected primary human blood monocytes provides us with an opportunity to answer specific questions about viral spread and persistence in in vivo-relevant myeloid cells that cannot be addressed with the more traditionally used replication-permissive cells. Our goal in examining the mechanisms whereby HCMV reprograms infected monocytes to promote viral dissemination is to uncover new targets for therapeutic intervention that would disrupt key viral survival and persistence strategies. Because of this important role in maintaining survival of HCMV-infected monocytes, our new data on the role of Bcl-2 regulation during viral infection represents a promising molecular target for mitigating viral spread and persistence.

Clinical significance of cytomegalovirus infection in patients with inflammatory bowel disease

Cytomegalovirus (CMV) infection is common in humans. The virus then enters a “latency phase” and can reactivate to different stimuli such as immunosuppression. The clinical significance of CMV infection in inflammatory bowel disease is different in Crohn’s disease (CD) and ulcerative colitis (UC). CMV does not interfere in the clinical course of CD. However, CMV reactivation is frequent in severe or steroid-resistant UC. It is not known whether the virus exacerbates the disease or simply appears as a bystander of a severe disease. Different methods are used to diagnose CMV colitis. Diagnosis is classically based on histopathological identification of viral-infected cells or CMV antigens in biopsied tissues using haematoxylin-eosin or immunohistochemistry, other tests on blood or tissue samples are currently being investigated. Polymerase chain reaction performed in colonic mucosa has a high sensitivity and a positive result could be associated with a worse prognosis disease; further studies are needed to determine the most appropriate strategy with positive CMV-DNA in colonic mucosa. Specific endoscopic features have not been described in active UC and CMV infection. CMV colitis is usually treated with ganciclovir for several weeks, there are different opinions about whether or not to stop immunosuppressive therapy. Other antiviral drugs may be used. Multicenter controlled studies would needed to determine which subgroup of UC patients would benefit from early antiviral treatment.

Human cytomegalovirus stimulates monocyte-to-macrophage differentiation via the temporal regulation of caspase 3

Monocytes are primary targets for human cytomegalovirus (HCMV) infection and are proposed to be responsible for hematogenous dissemination of the virus. Biologically, monocytes have a short life span of 48 h in the circulation, a period of time during which monocytes must make a cell fate decision on whether to undergo apoptosis or differentiate into a macrophage. We have previously shown that HCMV infection stimulates monocyte-to-macrophage differentiation; however, the mechanism(s) by which HCMV-infected monocytes simultaneously navigate the 48-h "viability gate" and undergo macrophagic differentiation has remained elusive. Studies have demonstrated that the level of caspase 3 and 8 activities in monocytes may mediate the delicate balance between apoptosis and macrophage colony-stimulating factor (M-CSF)-induced myeloid differentiation. Here, we show that HCMV infection, unlike M-CSF treatment, does not induce caspase 8 activity to promote myeloid differentiation. However, HCMV infection does induce a temporal activation of caspase 3, with only a low level of active caspase 3 being observed after the 48-h viability checkpoint. Consistent with the role of a time-dependent activation of caspase 3 in promoting myeloid differentiation, the inhibition of caspase 3 blocked HCMV-induced monocyte-to-macrophage differentiation. Temporal transcriptome and functional analyses identified heat shock protein 27 (HSP27) and Mcl-1, two known regulators of caspase 3 activation, as being upregulated prior to the 48-h viability gate following HCMV infection. Using small interfering RNAs (siRNAs), we demonstrate that HCMV targets the rapid induction of HSP27 and Mcl-1, which cooperatively function to precisely control caspase 3 activity in order to allow for HCMV-infected monocytes to successfully traverse the 48-h cell fate decision checkpoint and commence macrophage maturation. Overall, this study highlights a unique regulatory mechanism employed by HCMV to tightly modulate the caspase 3 activity needed to promote myeloid differentiation, a key process in the viral dissemination and persistence strategy.

Cytomegalovirus in inflammatory bowel disease: pathogen or innocent bystander?

The role of cytomegalovirus (CMV) in exacerbations of inflammatory bowel disease (IBD) remains a topic of ongoing debate. Current data are conflicting as to whether CMV worsens inflammation in those with severe colitis, or is merely a surrogate marker for severe disease. The interpretation of existing results is limited by mostly small, retrospective studies, with varying definitions of disease severity and CMV disease. CMV colitis is rare in patients with Crohn's disease or mild-moderate ulcerative colitis. In patients with severe and/or steroid-refractory ulcerative colitis, local reactivation of CMV can be detected in actively inflamed colonic tissue in about 30% of cases. Where comparisons between CMV+ and CMV- steroid-refractory patients can be made, most, but not all, studies show no difference in outcomes according to CMV status. Treatment with antiviral therapy has allowed some patients with severe colitis to avoid colectomy despite poor response to conventional IBD therapies. This article reviews the immunobiology of CMV disease, the evidence for CMV's role in disease severity, and discusses the outcomes with antiviral therapy.

PI3K-dependent upregulation of Mcl-1 by human cytomegalovirus is mediated by epidermal growth factor receptor and inhibits apoptosis in short-lived monocytes

Monocytes are a primary target for human CMV (HCMV) infection and are a key cell type responsible for hematogenous dissemination of the virus. Biologically, these cells have a short lifespan of 1-3 d in the circulation, yet infected cells remain viable for weeks despite the lack of viral antiapoptotic gene expression during this period. To understand the mechanism by which HCMV inhibits the initial phase of monocyte apoptosis, we focused on the viral modulation of early prosurvival cell signaling events after infection. We demonstrate in this study that the viral upregulation of the PI3K pathway promotes an early block in apoptosis after infection. Temporal transcriptome and protein analyses revealed Mcl-1, a member of the Bcl-2 family, was transiently induced in a PI3K-dependent manner during the early stages of HCMV infection. In accord with the survival studies, virally induced levels of Mcl-1 expression dissipated to mock levels by 72 h postinfection. Through the use of Mcl-1-specific small interfering RNA, we confirmed the functional role that Mcl-1 plays as a key early regulator of apoptosis in monocytes. Lastly, we showed that HCMV engagement and activation of the epidermal growth factor receptor during viral binding triggered the upregulation of Mcl-1. Overall, our data indicates that activation of the epidermal growth factor receptor/PI3K signaling pathway, via the PI3K-dependent upregulation of Mcl-1, is required to circumvent apoptosis in naturally short-lived monocytes during the early stages of HCMV infection, thus ensuring the early steps in the viral persistence strategy.

NF-kappaB and phosphatidylinositol 3-kinase activity mediates the HCMV-induced atypical M1/M2 polarization of monocytes

Human cytomegalovirus infection of monocytes stimulates a unique monocyte differentiation reprogramming resulting in polarization towards an M1 pro-inflammatory macrophage that simultaneously exhibits characteristics of an M2 anti-inflammatory macrophage. Our laboratory has previously shown that HCMV infection stimulates monocyte NF-kappaB and PI(3)K activities and now provides evidence that these cellular factors are essential for the HCMV-induced polarization of infected monocytes/macrophages. We find that the induction of NF-kappaB and PI(3)K activities following HCMV infection was required for the initiation of monocyte-to-macrophage differentiation. HCMV-infected monocytes treated with Bay11-7802 (an inhibitor of NF-kappaB activity) or LY294002 [an inhibitor of PI(3)K activity] prior to infection exhibited a small, round and monocyte-like undifferentiated morphology and the lack of CD68 upregulation (a macrophage differentiation marker). Detailed transcriptome analysis revealed 48%, 7% and 31% of HCMV-induced M1-associated genes were dependent on NF-kappaB, PI(3)K or both activities, respectively; while 100% of HCMV-induced M2-associated genes required both NF-kappaB and PI(3)K activities. Functionally, we demonstrated that NF-kappaB and PI(3)K activities were critical for the production of M1- and M2-associated cytokines/chemokines, in HCMV-induced differentiating monocytes. Supernatant from HCMV-infected monocytes pretreated with Bay11-7802 or LY294002 exhibited an 80% and 67% reduction in cell motility-inducing activity. Overall, these data show that HCMV usurps monocyte NF-kappaB and PI(3)K signal transduction pathways to induce the unique polarization of HCMV-infected monocytes needed for the earliest steps in the viral dissemination and persistence strategy.

Transcriptome analysis reveals human cytomegalovirus reprograms monocyte differentiation toward an M1 macrophage

Monocytes are primary targets for human CMV (HCMV) infection and are proposed to be responsible for hematogenous dissemination of the virus. Monocytes acquire different functional traits during polarization to the classical proinflammatory M1 macrophage or the alternative antiinflammatory M2 macrophage. We hypothesized that HCMV induced a proinflammatory M1 macrophage following infection to promote viral dissemination because, biologically, a proinflammatory state provides the tools to drive infected monocytes from the blood into the tissue. To test this hypothesis of monocyte conversion from a normal quiescent phenotype to an inflammatory phenotype, we used Affymetrix Microarray to acquire a transcriptional profile of infected monocytes at a time point our data emphasized is a key temporal regulatory point following infection. We found that HCMV significantly up-regulated 583 (5.2%) of the total genes and down-regulated 621 (5.5%) of the total genes>or=1.5-fold at 4 h postinfection. Further ontology analysis revealed that genes implicated in classical M1 macrophage activation were stimulated by HCMV infection. We found that 65% of genes strictly associated with M1 polarization were up-regulated, while only 4% of genes solely associated with M2 polarization were up-regulated. Analysis of the monocyte chemokinome at the transcriptional level showed that 44% of M1 and 33% of M2 macrophage chemokines were up-regulated. Proteomic analysis using chemokine Ab arrays confirmed the secretion of these chemotactic proteins from HCMV-infected monocytes. Overall, the results identify that the HCMV-infected monocyte transcriptome displayed a unique M1/M2 polarization signature that was skewed toward the classical M1 activation phenotype.

Anti-Human Cytomegalovirus Activity of Constituents from Sasa Albo-Marginata (Kumazasa in Japan)

Background:

Effective new anti-human cytomegalovirus (HCMV) agents and regimens need to be developed. We examined the anti-HCMV properties of crude extract (True World Extract of Bambuseae sasa [TWEBS]) and five compounds ( p-coumaric acid, 3-hydroxy-4-methoxyben-zaldehyde [vanillin], p-hydroxybenzaldehyde, 3-hydroxypyridine and 4',5,7-trihydroxy-3',5'-dimethoxyflavone [tricin]), isolated from Sasa albo-marginata, a bamboo known in Japan as Sasa.

Methods:

Among TWEBS and five compounds screened in a plaque reduction assay, four showed anti-HCMV activity in the MRC-5 human embryonic fibroblast cell line. The anti-HCMV mechanisms of the TWEBS was examined by western blot analysis using primary antibody specific for an immediate early (IE) antigen of HCMV, for a structural late antigen of HCMV and for β-actin.

Results:

Treatment of cells with ⩾0.001% of TWEBS inhibited the observable cytopathic effects of HCMV on infected cells. Western blot analysis demonstrated that TWEBS decreased the expression of IE antigen and late antigen of HCMV in the infected cells. Next, we examined the anti-HCMV properties of five compounds isolated from TWEBS. In a viral plaque reduction assay, tricin showed dose-dependent inhibitory properties with a 50% effective concentration of 0.17 µug/ml (selective index =1,205.8).

Conclusions:

The hot water extract (TWEBS) of Sasa albo-marginata, with tricin isolated from it, has anti-HCMV activity in MRC-5 cells. TWEBS and/or tricin are a novel compound with potential anti-HCMV activity. Future studies should evaluate these findings in vivo.

Anticytomegalovirus activity of pristimerin, a triterpenoid quinone methide isolated from Maytenus heterophylla (Eckl. & Zeyh.)

We examined the anticytomegalovirus properties of four compounds: pristimerin, the pristimerin analogue, lupeol and 2-acetylphenol-1-beta-D-glucopyranosyl (1 --> 6)-beta-D-xylpyranoside (acetophenol glycoside), isolated from Maytenus heterophylla, a Kenyan medicinal plant. The effects were studied on human cytomegalovirus (HCMV) replication in the human embryonic fibroblast cell line, MRC-5. In a viral plaque-reduction assay, pristimerin showed dose-dependent inhibitory properties with a 50% inhibitory concentration of 0.53 microg/ml (selective index = 27.9). The cells treated with pristimerin inhibited the cytopathic effects in HCMV-infected cells. Moreover, pristimerin suppressed viral replication without affecting the cell growth. Pristimerin inhibited the synthesis of viral DNA but had no virucidal effect on cell-free HCMV. Furthermore, Western blot analysis demonstrated that pristimerin decreased the amount of immediate early (IE) antigen (especially IE2) expression in the infected cells. These results suggest that pristimerin is a unique compound with potential anti-HCMV activity.

Roles of phosphatidylinositol 3-kinase and NF-kappaB in human cytomegalovirus-mediated monocyte diapedesis and adhesion: strategy for viral persistence

Infected peripheral blood monocytes are proposed to play a key role in the hematogenous dissemination of human cytomegalovirus (HCMV) to tissues, a critical step in the establishment of HCMV persistence and the development of HCMV-associated diseases. We recently provided evidence for a unique strategy involved in viral dissemination: HCMV infection of primary human monocytes promotes their transendothelial migration and differentiation into proinflammatory macrophages permissive for the replication of the original input virus. To decipher the mechanism of hematogenous spread, we focused on the viral dysregulation of early cellular processes involved in transendothelial migration. Here, we present evidence that both phosphatidylinositol 3-kinase [PI(3)K] and NF-kappaB activities were crucial for the HCMV induction of monocyte motility and firm adhesion to endothelial cells. We found that the beta(1) integrins, the beta(2) integrins, intracellular adhesion molecule 1 (ICAM-1), and ICAM-3 were upregulated following HCMV infection and that they played a key role in the firm adhesion of infected monocytes to the endothelium. The viral regulation of adhesion molecule expression is complex, with PI(3)K and NF-kappaB affecting the expression of each adhesion molecule at different stages of the expression cascade. Our data demonstrate key roles for PI(3)K and NF-kappaB signaling in the HCMV-induced cellular changes in monocytes and identify the biological rationale for the activation of these pathways in infected monocytes, which together suggest a mechanism for how HCMV promotes viral spread to and persistence within host organs.

Human cytomegalovirus (HCMV) infection of endothelial cells promotes naive monocyte extravasation and transfer of productive virus to enhance hematogenous dissemination of HCMV

Human cytomegalovirus (HCMV) pathogenesis is dependent on the hematogenous spread of the virus to host tissue. While data suggest that infected monocytes are required for viral dissemination from the blood to the host organs, infected endothelial cells are also thought to contribute to this key step in viral pathogenesis. We show here that HCMV infection of endothelial cells increased the recruitment and transendothelial migration of monocytes. Infection of endothelial cells promoted the increased surface expression of cell adhesion molecules (intercellular cell adhesion molecule 1, vascular cell adhesion molecule 1, E-selectin, and platelet endothelial cell adhesion molecule 1), which were necessary for the recruitment of naïve monocytes to the apical surface of the endothelium and for the migration of these monocytes through the endothelial cell layer. As a mechanism to account for the increased monocyte migration, we showed that HCMV infection of endothelial cells increased the permeability of the endothelium. The cellular changes contributing to the increased permeability and increased naïve monocyte transendothelial migration include the disruption of actin stress fiber formation and the decreased expression of lateral junction proteins (occludin and vascular endothelial cadherin). Finally, we showed that the migrating monocytes were productively infected with the virus, documenting that the virus was transferred to the migrating monocyte during passage through the lateral junctions. Together, our results provide evidence for an active role of the infected endothelium in HCMV dissemination and pathogenesis.

Aciclovir or ganciclovir universal prophylaxis of cytomegalovirus infection in liver transplantation: an economic analysis

BACKGROUND

Cytomegalovirus (CMV) following orthotopic liver transplantation can result in significant morbidity and mortality. Prophylaxis with oral aciclovir (ACV) or ganciclovir (GCV) for all transplant recipients (universal prophylaxis) may be beneficial, but which agent is more cost-effective is unknown.

METHODS

A single centre, retrospective study of all patients who had OLT at the Western Australian Liver Transplantation Service was performed. Patients received ACV from 1992 to 1998, and GCV from 1999 to 2001. A comparative cost-effectiveness analysis for the two groups was performed based on the mean total cost of the number of cases of CMV infection and disease as the clinical end-point.

RESULTS

The ACV group comprised of 55 patients and there were 24 in the GCV group. The incidence of CMV disease was 7% and 4% for the ACV and GCV groups, respectively (P > 0.05). For CMV infection it was 16% and 8%, respectively (P > 0.05). GCV prevented more cases of CMV infection and disease than ACV but at an incremental cost of dollars A20,000 (dollars US10,172) per case prevented. Overall, ACV was more cost-effective than GCV by dollars A2200 (dollars US1119) per person. The cost benefit of ACV was derived principally through a reduced pharmaceutical cost. Both agents were well tolerated without development of antiviral resistance.

CONCLUSIONS

Universal prophylaxis of CMV infection-following liver transplantation with aciclovir is more cost-effective than with ganciclovir.

Human cytomegalovirus induces monocyte differentiation and migration as a strategy for dissemination and persistence

Human cytomegalovirus (HCMV) pathogenesis is characterized by multiple organ system involvement due to viral spread to host organs after a cell-associated viremia. The cell type responsible for HCMV dissemination is unknown. Monocytes are the most likely candidate since they are the predominant cell type infected in the blood. However, monocytes are not productive for viral replication and are abortively infected. The results presented here provide a potential answer to this conundrum. We report that primary HCMV infection of monocytes induces transendothelial migration and monocyte-to-macrophage differentiation and that these HCMV-differentiated macrophages are productive for viral replication. Together, our data suggest a novel mechanism for HCMV pathogenesis; HCMV induces cellular changes in monocytes to promote viral replication and spread to host organs.

HCMV activates PI(3)K in monocytes and promotes monocyte motility and transendothelial migration in a PI(3)K-dependent manner

Human cytomegalovirus (HCMV) is a leading cause of morbidity and mortality in immunocompromised hosts. In immunocompetent hosts, HCMV is associated with chronic inflammatory diseases including atherosclerosis. Monocytes and macrophages are proposed to play key roles in HCMV dissemination to host tissue, and their infection provides a biological link between the lifecycle of HCMV and disease pathology. We hypothesize that viral spread occurs via a mechanism in which infected peripheral blood monocytes, which are nonpermissive for viral replication, extravasate into host tissue and subsequently differentiate into permissive macrophages. Supporting this hypothesis, we recently showed that HCMV specifically induced the differentiation of monocytes into macrophages that become permissive for viral replication. To expand our understanding of HCMV pathogenesis, we next examined monocyte activation and migration, the first events in viral pathogenesis. We show here that HCMV up-regulates phosphatidylinositol 3,4,5 triphosphate kinase [PI(3)K] activity and that this increased PI(3)K activity is essential for infected monocyte-transendothelial migration. This increase in migration occurs through the up-regulation of cell motility in a PI(3)K-dependent process. Last, we show that these activated monocytes express a number of inflammatory mediators via PI(3)K signaling. We propose that the up-regulation of monocyte migration and immune mediators by HCMV infection is required for the hematogenous dissemination of the virus and as a consequence, could promote chronic inflammatory diseases associated with HCMV infection.

Valaciclovir prophylaxis of cytomegalovirus infection and disease in renal transplantation: an economic evaluation

BACKGROUND

Cytomegalovirus (CMV) disease is a major cause of morbidity and mortality in solid organ transplant patients and is associated with large additional healthcare expenditures. An economic evaluation of valaciclovir CMV prophylaxis in a renal transplant population is reported.

METHODS

Medical resource use data were collected alongside a multicenter multinational randomized, placebo-controlled, double-blind trial of valaciclovir CMV prophylaxis in renal transplantation. Patients were stratified into donor seropositive/recipient sero-negative (D+R-) and recipient seropositive (R+) groups. Patients were followed-up 6 months posttransplant. A cost-effectiveness analysis from the perspective of the French health care system was performed using the number of cases of CMV disease avoided at 6 months as the clinical endpoint.

RESULTS

Resource use was significantly increased among patients who developed CMV disease compared to those who did not develop disease. In the high risk D+R- group, valaciclovir prophylaxis was associated with an average of 5.5 fewer inpatient hospital days (P < OR =0.05) and with significantly lower use of other healthcare resources. In the R+ group, valaciclovir prophylaxis prevented cases of CMV disease at a marginally greater mean cost per patient compared with placebo. For D+R- patients valaciclovir prophylaxis was therefore an economically superior strategy, resulting in fewer cases of CMV disease and lower total mean healthcare expenditures.

CONCLUSIONS

Valaciclovir CMV prophylaxis in renal transplantation is a more cost-effective therapy compared with placebo, in the high-risk D+R- patient population. For the R+ group, the incremental cost per case of CMV disease was modest.

Cost-effectiveness model of cytomegalovirus management strategies in renal transplantation. Comparing valaciclovir prophylaxis with current practice

BACKGROUND

Cytomegalovirus (CMV) disease may occur following renal transplantation and has been shown to have health and cost consequences in this setting.

OBJECTIVE

To compare the cost effectiveness of different CMV management strategies for renal transplant patients: prophylaxis with (i) oral valaciclovir or (ii) intravenous ganciclovir; viral testing for CMV followed by (iii) pre-emptive therapy with intravenous ganciclovir or (iv) adjustment of immunosuppression and intensive monitoring; or (v) waiting to treat when CMV disease develops.

METHODS

A decision-tree model was constructed that included the different management strategies for the donor seropositive/recipient seronegative (D+R-) population. Clinical outcomes for the D+R- population came from clinical trials. Treatment algorithms and costs for CMV syndrome and tissue invasive disease were developed from published literature and UK physician interviews. One- and 2-way sensitivity analyses were performed.

STUDY PERSPECTIVE

UK National Health Service.

RESULTS

Prophylaxis with either oral valaciclovir or intravenous ganciclovir dominated (lower costs and fewer cases of CMV disease) the pre-emptive treatment and wait-and-treat strategies. The cost per patient was from 157 Pounds to 438 Pounds higher with oral valaciclovir prophylaxis compared with intravenous ganciclovir prophylaxis and the incremental cost per case of CMV disease avoided with valaciclovir prophylaxis ranged from 2243 Pounds to 8111 Pounds (1996 values). These results are sensitive to the efficacy of intravenous ganciclovir prophylaxis and CMV management costs.

CONCLUSIONS

For D+R- renal transplant patients, prophylaxis is the dominant (more effective and less costly) management strategy compared with pre-emptive and wait-and-treat strategies. The cost per patient with oral valaciclovir prophylaxis compared with intravenous ganciclovir prophylaxis is slightly higher in our base case scenario, but may be lower under reasonable alternative assumptions.

Cloning and epitope mapping of a functional partial fusion receptor for human cytomegalovirus gH

A cDNA clone encoding a partial putative human cytomegalovirus (HCMV) gH fusion receptor (CMVFR) was previously identified. In this report, the cDNA sequence of CMVFR was determined and the role of this CMVFR in HCMV/cell fusion was confirmed by rendering fusion-incompetent MOLT-4 cells susceptible to fusion following transfection with receptor cDNA. Blocking experiments using recombinant gH or either of two MAbs (against recombinant gH or purified viral gH:gL) provided additional evidence for the role of gH binding to this protein in virus fusion. An HCMV-binding domain of 12 aa in the middle hydrophilic region of CMVFR was identified by fusion blocking studies using synthetic receptor peptides. The 1368 bp cDNA of CMVFR contained a predicted ORF of 345 aa with two potential membrane-spanning domains and several possible nuclear localization signals. A search of sequence databases indicated that CMVFR is a novel protein. Further characterization of this cell membrane protein that confers susceptibility to fusion with the viral envelope should provide important information about the mechanism by which HCMV infects cells.

Costs and outcomes of prolonged cytomegalovirus prophylaxis to cover the enhanced immunosuppression phase following lung transplantation

BACKGROUND

Cytomegalovirus (CMV) disease is one of the major challenges of lung transplantation that may determine outcome. The benefits of ganciclovir prophylaxis seem indisputable, but no consensus has been reached on the optimal duration of therapy. Results with different protocols suggest that efficacy is related to the duration of treatment.

MATERIALS AND METHODS

To evaluate the additional effect of a prolonged regimen throughout the maximal immunosuppression phase, we conceived a protocol administering ganciclovir, 5 mg/kg/d for 20 weeks from the first postoperative day, to all CMV-seropositive patients undergoing lung transplantation or receiving the lung from a seropositive donor. Virus shedding was routinely measured in body fluids including through BAL. Costs and outcomes are compared with those in shorter prophylaxis protocols from previous reported studies.

RESULTS

Of 30 lung transplant recipients, 22 patients at risk for CMV reactivations were observed for (mean SD) 22.9 +/- 13.2 months. CMV infections were detected in eight patients 8.6 +/- 5.1 months after transplantation. CMV pneumonitis developed in one patient 9 months following the transplant event. Prolonged IV ganciclovir prophylaxis was, in general, well tolerated. However, five patients had bacteremia and one had a local thrombosis, with no long-term consequences. A prescription for 8 additional weeks of prophylaxis to cover the whole period of enhanced immunosuppression decreased the cumulative incidence of first CMV infections by 29% 1 year after transplantation compared to 12-week regimens reported in other studies that indicated a 50% reduction in the incidence of first CMV infection. The total cost of 20 weeks of IV ganciclovir prophylaxis was $6,010 (US dollars) per patient more expensive than 12 weeks of IV ganciclovir therapy. This was not offset by the reduced requirement for treatment of infections. Indeed, extrapolating to our cohort of patients, the additional cost per patient was seven times greater than the treatment for the infections that were reported after the 12-week prophylaxis protocol.

CONCLUSION

Prolonging ganciclovir prophylaxis to 20 weeks decreased by half the rates of CMV infection when compared to reports from centers using a shorter protocol of 12 weeks for ganciclovir prophylaxis. Additionally, a delay in the onset of the first infection was observed. Nevertheless, the increase in costs and the discomfort of long-term use of venous catheters are important factors that may favor a shorter regimen of 12 weeks followed by preemptive therapies each time CMV infections occur.

Prevalence of cytomegalovirus in the gastrointestinal tract of renal transplant recipients with persistent abdominal pain

Abdominal pain occurs frequently in renal transplant recipients receiving mycophenolate mofetil (MMF) therapy. The cause of this abdominal pain has not been fully elucidated, but may involve local irritation, as well as inhibition of rapidly dividing cells of the gastrointestinal (GI) tract. This milieu of inflammation and added immunosuppression is conducive to activation of cytomegalovirus (CMV). We therefore sought to find the prevalence of active CMV in patients presenting with abdominal pain on maintenance MMF therapy. All patients receiving a renal transplant at our center from March 1, 1997, to September 1, 1997, were studied. Any patient presenting with midepigastric pain for greater than 3 days underwent esophagogastroduodenoscopy (EGD) with biopsy. CMV was diagnosed by the presence of inclusion bodies and immunohistochemical studies. Ten patients presented with persistent midepigastric pain; nine of these patients had evidence of GI CMV. Patients who were CMV negative and received an allograft from CMV-positive donors and those with leukopenia were at significantly increased risk for the development of abdominal pain. In our study population, the majority of patients on maintenance MMF therapy who presented with persistent midepigastric pain had evidence of active CMV infection in the upper gastrointestinal tract.

Two clinical isolates and the Toledo strain of cytomegalovirus contain endothelial cell tropic variants that are not present in the AD169, Towne, or Davis strains

The highly fibroblast-passaged AD169, Towne, and Davis strains of cytomegalovirus (CMV) were found to have a restricted capacity to infect endothelial cells in vitro. Although such replication could be increased by a combination of low speed centrifugation and sodium butyrate treatment, the extracellular virus produced was infectious for fibroblasts but not for endothelial cells. In contrast, the low passage Toledo strain, and a low passage fibroblast-grown clinical isolate of CMV, C1F, could be continually passaged in endothelial cells, giving the strains C1FE and Toledo.E. Whilst, using the conditions described above, initial infection of endothelial cells with AD169 or C1F resulted in similar titres of extracellular virus as assayed on fibroblasts, only the virus from the C1F strain was infectious for endothelial cells. Passage of C1F in fibroblasts decreased its ability to infect endothelial cells, whilst retaining equal ability to infect fibroblasts. Although endothelial-cell-passaged cell-free C1FE virus was endothelial cell-tropic, it was still much more infectious for fibroblasts than for endothelial cells. It is concluded that the C1F and Toledo strains, but not the AD169, Towne, or Davis strains, contained endothelial cell tropic variants, which could be lost on passage through fibroblasts, but retained on passage through endothelial cells. Furthermore, virus in an ex vivo source of CMV, a blood specimen, was found to be more tropic for fibroblasts than for endothelial cells, suggesting that in vivo CMV exists as quasi strains with different cell tropism, some of which might be lost in vitro by passage in an inappropriate cell type.

Adenovirus colitis in human immunodeficiency virus infection: an underdiagnosed entity

Adenovirus infection of the gastrointestinal tract in human immunodeficiency virus (HIV)-infected patients is rarely reported, probably because of a lack of familiarity of most pathologists with diagnostic criteria during routine light microscopy and possible misidentification as cytomegalovirus infection. We studied colonoscopic biopsy specimens from 135 HIV-infected patients with clinically suspected cytomegalovirus colitis during a 4.5-year period to morphologically identify the presence of adenovirus infection. Immunohistochemical staining for adenovirus was performed for confirmation on all suspected cases. Adenovirus infected cells showed characteristic amphophilic or eosinophilic nuclear inclusions, predominantly affecting the surface epithelium and characteristically involving goblet cells. Sixteen cases showed morphologic features of adenovirus infection, all confirmed by immunohistochemistry. Twelve cases also showed cytomegalovirus infection, whereas 4 showed adenovirus alone. In 10 cases, adenovirus colitis was not recognized during initial routine histopathologic diagnostic evaluation. Adenovirus inclusions also were discovered in the stomach, the duodenum, and the liver in single cases. Conclusions are as follows: (1) Adenovirus colitis has been underdiagnosed at our institution and, we suspect, in general. (2) The morphologic features and nuclear inclusions of adenovirus colitis are characteristic and can be identified reliably by routine light microscopy. (3) Adenovirus infection also may be diagnosed morphologically in extracolonic sites, such as the stomach, the small intestine, and the liver. (4) Coinfection of adenovirus with cytomegalovirus and other agents is seen frequently, but, less frequently, adenovirus may be identified as a sole pathogen.

Clinical features and outcomes of HIV-related cytomegalovirus pneumonia

OBJECTIVE

To describe the characteristics and outcomes of HIV-infected patients with biopsy-proven cytomegalovirus (CMV) pneumonia.

DESIGN

Retrospective study.

SETTING

A 900-bed acute facility in New York City.

PATIENTS

Eighteen HIV-infected patients with pathologically confirmed CMV inclusions in lung tissue without other pathogens and 36 control patients with biopsy-proven Pneumocystis carinii pneumonia (PCP) selected for comparisons by computer-generated random sequential numbers.

MAIN OUTCOME MEASURES

Demographic, clinical, laboratory, radiological findings, and in-hospital mortality.

RESULTS

Eighteen HIV-infected patients were found to have CMV lung infection alone. Pathologic findings were pneumonitis (n = 11); pneumonitis and pulmonary vasculitis (n = 1); and CMV inclusions alone (n = 6). All presented with respiratory symptoms (cough or dyspnea), 89% had fever, 83% had radiological abnormalities, and 56% had severe hypoxemia. The pulmonary presentation was similar except for higher lactate dehydrogenase (median, 449 versus 329 IU/l; P = 0.03) and presence of pleural effusions (33 versus 0%; P = 0.001) in CMV patients. Multivariate analysis showed that CD4 counts < or = 12 x 10(6)/l (odds ratio; 9.2; P = 0.029) and extrapulmonary CMV (odds ratio, 20.4; P = 0.039) were independently associated with CMV pneumonia. Seventeen patients received specific anti-CMV therapy for a mean of 22 +/- 13 days. In-hospital mortality was higher in patients with CMV pneumonia (odds ratio, 11.9; P = 0.002). The median time from admission to death was 31 days.

CONCLUSIONS

CMV lung infection was seen in severely immunosuppressed HIV-positive patients and associated with clinical pneumonitis with high early mortality. Although the clinical features resemble PCP, the presence of extrapulmonary CMV disease should suggest the diagnosis of CMV pneumonia.

Summary of the International Consensus Symposium on Advances in the Diagnosis, Treatment and Prophylaxis and Cytomegalovirus Infection

CMV infection and CMV disease can be difficult to differentiate and the diagnosis is usually based on a compatible clinical picture and the results of a diagnostic test for CMV. The only exception to this rule is in HIV-infected patients where fundoscopy is sufficient to diagnose CMV retinitis. Of the current diagnostic tests, qualitative and quantitative PCR, branched DNA and Hybrid Capture, are the most promising. The pp65 antigenemia assay has the disadvantage of being more labor-intensive than the DNA based tests. Preliminary data show that a positive qualitative PCR in a HIV-infected patient has a predictive value for the development of CMV retinitis. However, of the patients positive by qualitative PCR, those with high viral loads in quantitative PCR were at the greatest risk of CMV disease. This might make it possible to identify with great certainty the patients who will go on to develop CMV retinitis, thereby decreasing the number of patients eligible for preemptive or prophylactic therapy and increasing the cost-benefit of this therapeutic measure. Quantitative test might also be useful in monitoring response to therapy, but randomized trials comparing the test are needed. Prophylactic antiviral agents should not be used in seronegative transplant recipients receiving organs from seronegative donors. In high-risk transplant recipients, ganciclovir should be used. CMV vaccines are useful for the protection of babies from CMV seronegative mothers against congenital CMV disease. It also may be useful in seronegative transplant recipients receiving a seropositive donor organ, although the benefit of chemo prophylaxis may surpass that of vaccine. HIV-infected patients with CMV retinitis who relapse under either ganciclovir or foscarnet benefit from subsequent combination therapy, rather than switching to the other drug. However, the cost is high in terms of quality of life. Intravitreal therapy for CMV retinitis is very efficacious, suggesting that drug delivery is a problem in systemic therapy. However, intravitreal therapy does not protect against the development of CMV retinitis in the contralateral eye or from CMV disease elsewhere. Therefore, systemic therapy should be added. CMV disease of the CNS should be diagnosed early and treated agressively, possible with combination therapy. A diagnosis of CMV disease should be based on a compatible clinical picture and the demonstration of CMV in CSF by DNA or antigen assays which are more sensitive than culture.

Prophylactic treatment of cytomegalovirus infection with traditional herbs

Hot water extracts of four traditional herbs, Geum japonicum, Syzygium aromaticum, Terminalia chebula and Rhus javanica, which have been shown to have anti-herpes simplex virus (HSV) activity in vivo, were examined for anti-cytomegalovirus (CMV) activity in vitro and in vivo in this study. They inhibited replication of human CMV and murine CMV (MCMV) in vitro. These anti-CMV activities in vivo were examined in an MCMV infection model using immunosuppressed mice. Mice were subcutaneously treated with various doses of cyclosporine, and immunosuppression and MCMV infection were monitored by suppression of antibody production and virus yield in the lung, respectively. Each herbal extract was orally administered to mice treated with 50 mg/kg of cyclosporine from a day before intraperitoneal infection, and the efficacy of herbs was evaluated by the reduction in the virus yield in the lung. Among them Geum japonicum, Syzygium aromaticum, and Terminalia chebula significantly suppressed MCMV yields in lungs of treated mice compared with water treatment. Efficacy of oral treatment with 750 mg/kg per day of Geum japonicum extract was similar to that of the intraperitoneal administration of 2 mg/kg per day of ganciclovir in increasing the body weight of infected mice and reducing the virus yield in the lungs. These herbs may be beneficial for the prophylaxis of CMV diseases in immunocompromised patients.

Cytomegalovirus myocarditis following liver transplantation

Cytomegalovirus (CMV) infections are commonly found in patients on immunosuppressive therapy following liver transplantation. However, acute myocarditis is an extremely rare manifestation of CMV infection in this setting. We report the case of a patient who developed acute myocarditis with severe biventricular failure with a cardiac ejection fraction of less than 10%, 6 weeks following orthotopic liver transplantation. Systemic CMV infection was diagnosed on the basis of a clinical viraemia, the presence of CMV antigen in urine, blood, and throat swab, and an associated four-fold rise in serum antibody titres to CMV. A full recovery ensued following treatment with standard anti-cardiac failure therapy and a 10 day course of intravenous ganciclovir.

Mixed viral infections: detection and management

An analysis was done of the incidence and nature of mixed virus infections diagnosed in the same clinical specimen from immunocompetent patients; respiratory viruses were emphasized. Few studies have addressed mixed viral infections in any systematic fashion. The relevant studies reviewed focused on clinical relationships or diagnostic methods. Data relating to multiple infections were usually derived incidentally to the purpose of the investigations. Sixty-three percent of the reports with data on mixed infections identified them in < 5% of the total number of viral infections. Respiratory syncytial virus was the most common coinfecting virus, and respiratory syncytial virus and influenza virus were the most common virus pair identified. In considering rapid diagnostic techniques, in 87% of the reports with available data a virus was diagnosed in > 10% of specimens that were negative for the virus targeted by one method. There was no indication that mixed infections were associated with increased disease in immunocompetent patients or in certain immunocompromised patients. Immunocompromised patients, however, appeared to have a greater incidence of multiple infections. Mixed infections of single cells also occur and may have important clinical implications relative to reactivation of latent viruses and enhanced disease. The requirement for a comprehensive strategy for viral diagnosis involving multiple techniques was indicated by these findings.

Virus-specific antibodies to Epstein-Barr virus, varicella-zoster virus and rubella virus in renal transplant patients with cytomegalovirus infections

Renal transplant patients with primary and recurrent cytomegalovirus (CMV) infection had higher antibody titres to Epstein-Barr virus viral capsid antigen (EBV-VCA-IgG) before and after transplantation than healthy blood donors. The geometric mean titres (GMT) of EBV-VCA-IgG were higher in renal transplant patients without CMV infection than in renal transplant patients with CMV infection. Four-fold or greater rises in EBV-VCA-IgG antibody were detected in six patients and a similar rise in antibody to EBV early antigen (EBV-EA-IgG) was detected in one other patient. IgM antibody to EBV-VCA (EBV-VCA-IgM) was detected in only three of these patients. EBV-EA-IgG was present in 39% patients and in 30% control subjects. IgG titres to varicella zoster virus (VZV-IgG) and rubella virus (rubella HI) were higher in patients without CMV infection compared to the patients with CMV infection. Raised titres were detected to VZV in five patients and to rubella virus in three patients. Reductions in antibody titre of four-fold or more were also detected in EBV-EA-IgG (one patient) and to rubella virus (one patient). Raised antibody titres to EBV, VZV, and rubella virus in renal transplant patients may indicate reactivation of these viruses without any symptoms.

Neuropathologic findings after liver transplantation

Neuropathologic findings are described in 37 patients autopsied after one or more orthotopic liver transplants. Gross or microscopic lesions were observed in almost all patients, including anoxic-ischemic change, hemorrhages and/or infarcts, and opportunistic infections by fungi (most commonly Aspergillus) and rarely viruses (cytomegalovirus). Central pontine and extra-pontine myelinolysis was commonly observed, and appeared to result from severe multifactorial metabolic abnormalities in the perioperative period. Low-grade (microglial nodule) encephalitis without an obvious pathogen was often encountered. Common clinical neurologic abnormalities included encephalopathy, seizures (myoclonic, focal or generalized), obtundation and coma. These were found more commonly than focal findings, but clinical features in a given patient were not uniformly predictive of underlying neuropathologic change.

Adenovirus infection of the kidney: mass formation in a patient with Hodgkin's disease

Adenovirus (AV) infection usually has a benign course in normal hosts; however, in immunocompromised patients, AV may cause pneumonia, cystitis, or disseminated disease with substantial morbidity and even mortality. Although pulmonic AV involvement is common, infection of the kidney is unusual. The histologic findings previously described include tubular necrosis with interstitial inflammation and glomerulonephritis. We report a case of an AV-induced unilateral mass lesion in the kidney of a patient with Hodgkin's disease (HD) following bone marrow transplantation.

Prevention of cytomegalovirus infection in the pediatric renal transplant recipient

Cytomegalovirus (CMV) infection is the most important single infectious complication of organ transplantation, affecting more than 70% of transplant recipients. Its emergence as a major pathogen has coincided with the use of cytotoxic therapy. Manifestations of serious CMV disease include: pneumonia, hepatitis, gastrointestinal disease, leukopenia and chorioretinitis. CMV is associated with superinfection with opportunistic organisms, graft failure and increased mortality. Serious infection most frequently occurs with primary CMV infection in which latently infected cells from CMV-positive donors are given to seronegative recipients. Pediatric patients who have a lower pre-transplant rate of CMV seropositivity are at particularly high risk of developing serious CMV disease. Preventative efforts range from the ideal but impractical use of only CMV-negative donors (organ and blood products), to the use of CMV hyperimmune globulin and antiviral chemotherapy. Data support the use of prophylactic hyperimmune globulin and preliminary information supports the use of prophylactic high-dose acyclovir in renal transplant patients. Prophylactic gancyclovir alone or with hyperimmune globulin and pre-transplant vaccination with live-attenuated Towne strain CMV vaccine remain investigational.

The prevention of cytomegalovirus disease in renal transplantation

Primary cytomegalovirus (CMV) disease can be prevented in renal transplant recipients with the use of either CMV hyperimmune globulin (CMVIg) or acyclovir. Started within 72 hours of transplantation and continued for 16 weeks posttransplant, CMVIg decreases the incidence of primary CMV disease from 60% to 21%. Acyclovir administered preoperatively and for 3 months thereafter decreases the incidence of CMV disease from 29% to 8% and is the most cost-effective therapy. The effectiveness of these preparations in preventing CMV reinfection or reactivation has not been established. The utility of therapies other than CMVIg or acyclovir for the prevention of CMV disease has not been proven; CMV vaccination is ineffective, polyvalent immunoglobulins require further study, and interferon alpha (IFN-alpha) has been associated with frequent irreversible rejection reactions and therefore should not be used for CMV prophylaxis. Although further investigation is necessary, patients at risk for primary CMV disease should receive prophylactic therapy with either CMVIg or acyclovir.

Cytomegalovirus infection among tuberculosis patients in a chest hospital in Nigeria

A serological study was carried out in Ibadan, Nigeria to determine the prevalence of inapparent infection with cytomegalovirus among tuberculosis patients and its relation to the epidemiology of the virus in this environment. A total of 360 sera from 161 tuberculosis patients, 89 patients other than tuberculosis and 110 healthy voluntary blood donors were examined for antibody to cytomegalovirus by the complement fixation test. One hundred and forty-one (87.6%) of the tuberculosis patients, 45 (50.6%) patients other than tuberculosis and 60 (54.6%) healthy blood donors had a complement fixing antibody to cytomegalovirus. Although the total prevalence (68.3%) of complement fixing antibody against cytomegalovirus in all the groups is high, it is higher among the tuberculosis patients than the other groups in the same environment. This shows that tuberculosis which is still a major health problem in Nigeria may be playing a significant role in the spread of cytomegalovirus in the country.

Viral and toxoplasma gondii infections in children after liver transplantation

The incidence and morbidity of viral and Toxoplasma gondii infections were studied in 40 children who underwent liver transplantation between December 1983 and February 1988. The incidence of primary and reactivated cytomegalovirus (CMV) infection was 19% and 47%, respectively; primary infection caused clinical disease in all five cases affected and was fatal in one. Primary Epstein-Barr virus (EBV) infection occurred in 10 (26%) recipients but caused only mild disease. No reactivated EBV infection was recorded and no lymphoproliferative disorders associated with EBV were found after a maximum of four years' follow up. Adenovirus infection occurred in seven (18%) patients; this was associated in one case with fatal pneumonia and fulminant hepatitis, but otherwise with only mild respiratory disease. Primary T gondii infection was detected in one patient who remained asymptomatic. Other viruses causing infection included herpes simplex, varicella zoster, and respiratory syncytial virus. Surveillance for these infections and the long term sequelae should be included in the follow up of all children who undergo transplantation.

Rapid and accurate viral diagnosis

In recent years, there has been increased recognition of the importance of viral infections. In addition, new antiviral agents have become available. These factors have led to a marked increase in utilization of viral diagnostic services. In this review, both conventional and rapid methods for viral diagnosis are presented, with emphasis on recent advances. The antiviral agents currently available and the major drugs under investigation are also briefly discussed. It is hoped that this review will serve as a useful adjunct for the management of patients with virus infections.

Cytomegalovirus infections in heart and heart and lung transplant recipients

Of the first 166 heart and 15 heart and lung transplant recipients at Papworth Hospital, Cambridge, who survived for more than one month after transplantation, 162 were investigated for cytomegalovirus (CMV) infection by serological methods. Altogether, 73 (45%) developed CMV infection after transplantation: 30 (18.5%) had acquired primary infection and 43 (26.5%) reactivation or reinfection. Six patients died of primary infection, probably acquired from the donor organ. Recipients negative for CMV antibody who received an organ from an antibody positive donor had the most severe disease. Heart and lung transplant recipients experienced more severe primary CMV infection than those in whom the heart alone was transplanted. The most sensitive and rapid serological method was a mu-capture enzyme linked immunosorbent assay (ELISA) for detecting CMV specific IgM, the amount of which was often of prognostic value and influenced the management of patients.

Cytomegalovirus-specific antibody responses in renal transplant patients with primary and recurrent CMV infections

Cytomegalovirus (CMV) specific immunoglobulin G (IgG) and immunoglobulin M (IgM) antibody responses were measured before and after renal transplantation in 20 patients with primary CMV infection and in 16 patients with recurrent CMV infection. In primary CMV infection IgG antibody titres to late antigen (IgG-LA) measured by indirect fluorescence (IFA) were approximately seven times higher than those obtained by the complement fixation test (CFT). In contrast, in recurrent CMV infection this difference was found to be about twofold. Virus-specific IgM antibody to late antigen (IgM-LA) was detected in 100 percent of patients with primary CMV infection and in only 50 percent of patients with recurrent CMV infection. The IgM-LA titres were highest in primary CMV infection and reached peak levels at approximately 10 weeks post transplantation, whereas in recurrent CMV infection the IgM-LA titres were lower and reached peak levels at three months post transplantation. Moreover, IgM-LA was found to persist in patients from both groups at nine months post transplantation. IgM antibody to early antigen (IgM-EA) was not detected in any patient in this study. However, significant fourfold titre rises in IgG antibody to EA (IgG-EA) were detected in 100 percent of patients with recurrent CMV infection and in 50 percent of patients with primary CMV infection. These results clearly show the difference in antibody responses to the various antigens of CMV in patients with primary and recurrent CMV infection.